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The in vitro antidiabetic and antihyperlipidemic activities of an alcoholic extract of Trigonella stellata were evaluated in terms of the activation of PPARα and PPARγ in human hepatoma (HepG2) cells. The extract was investigated phytochemically, aiming at the isolation of the most active compounds to be used as a platform for drug discovery. Three new isoflavans, (3S,4R)-4,2′,4′-trihydroxy)-7-methoxyisoflavan (1), (3R,4S)-4,2′,4′-trihydroxy-7-methoxy-4′-O-β-d-glucopyranosylisoflavan (2), and (2S,3R,4R)-4,2′,4′-trihydroxy-2,7-dimethoxyisoflavan (3), were isolated and characterized along with the five known compounds p-hydroxybenzoic acid (4), 7,4′-dihydroxyflavone (5), dihydromelilotoside (6), quercetin-3,7-O-α-l-dirhamnoside (7), and soyasaponin I (8). The structures of 1–3 were elucidated using various spectroscopic techniques including HRESIMS and 1D and 2D NMR. The absolute stereochemistry of the new isoflavans (1–3) was determined using both experimental and calculated electronic circular dichroism a...

In this study, an ultra-performance liquid chromatography (UPLC)/photodiode array method was developed for the simultaneous determination of trigonellan glucoside (1), isotrigonellan (2), and methoxy-isotrigonellan (3) in Trigonella stellata extract using an external standard method. The extract was prepared using a standardized method by maceration of the dried plant material in ethanol. The 3 isoflavans (1-3) were separated on an Acquity UPLC C18 column using gradient elution with a mobile phase consisting of 0.1% (v/v) formic acid aqueous solution and 0.1% (v/v) formic acid in acetonitrile, and ultraviolet detection. The method provides a linear correlation for all analytes over the investigated ranges with all correlation coefficients greater than 0.998. The validated lower limits of quantitation were 53, 127, and 5 μg/mL for isoflavans 1, 2, and 3, respectively. Intraday and interday precisions (percent relative SD [RSD%]) were less than 8.3% and accuracy (RE%) ranged from 90% to 100%. The method’s capability to remain unaffected by small, but deliberate variations in method parameters (method’s reliability during normal usage) described by the robustness showed RSD% less than 4.6% measured by varying 3 different parameters. The validated method was successfully applied to simultaneously determine the concentration of the 3 new isoflavans having anti-inflammatory and antidiabetic activities. The results revealed that the validated method can be used for quality control of herbal preparations containing these or similar isoflavans that are marketed for the prevention of inflammation and as antidiabetics.

A high-performance thin-layer chromatographic (HPTLC) method has been established for determination of sildenafil citrate in commercial products. The compounds were separated on silica gel, with CHCl 3 -MeOH-diethylamine, 90 + 10 + 1 ( v/v ), as mobile phase, and the analyte spots were quantified densitometrically at λ = 305 nm. Recovery of sildenafil citrate was 100.6 and 98.2%, for pure and spiked samples, respectively. Method precision and specificity were also validated. The method was used for determination of sildenafil in four pharmaceutical products and three aphrodisiac herbal preparations which were claimed to be totally natural. Levels of sildenafil in the pharmaceutical products ranged from 49.7 to 50.5 mg per tablet. Sildenafil was also detected in one herbal preparation at a concentration of 85.0 mg per capsule.

Chemical investigation of the Red Sea sponge Pseudoceratina arabica has led to the isolation and identification of seven brominated compounds including two new bromotyramine derivatives, hydroxymoloka'iamine (2) and moloka'iakitamide (6), and a new brominated phenolic compound, ceratinophenol A (5), together with the known compounds moloka'iamine (1), ceratinamine (3), 5-bromo-2,3-dihydroxy-6-methoxybenzaldehyde (4), and psammaplysin-A (7). Biological evaluation of these metabolites indicated that moloka'iamine and moloka'iakitamide possess significant parasympatholytic effects on isolated rabbit heart and jejunum. This finding has important implications for further biological investigation of this class of compounds. Moreover, these compounds showed weak antibacterial and antifungal activities.

Bulbs of Pancratium maritimum were found to contain a new glucosyloxy phenolic metabolise as well as 14 known Amaryllidaceae alkaloids. The structure of the phenolic metabolite was elucidated by spectroscopic and chemical methods, and it was identified as narciclasine-4- O -β- d -glucopyranoside. When tested in Artemia salina and potato disc assays the new glucoside showed cytotoxic and antitumour activity very similar to narciclasine.

Reinvestigation of the Red Sea sponge Suberea mollis afforded two new bromotyrosine-derived alkaloids, subereamollines A (1) and B (2), two new brominated phenolic compounds, subereaphenols B (7) and C (9), and the known compounds aerothionin (3), homoaerothionin (4), 11,19-dideoxyfistularin-3 (5), aeroplysinin-1 (6), and aeroplysinin-2 (8). The structure determination of the isolated compounds was assigned using one- and two-dimensional NMR spectra and HRFABMS data. The antimicrobial and antioxidant activities of the isolated compounds have been evaluated. Aeroplysinin-1 displayed significant antimicrobial activity against S. aureus, P. aerugenosa, and K. pneumoniae. The isolated compounds were examined for their antioxidant activity using a 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) solution-based chemical assay. Among the tested compounds, only subereaphenols B and C displayed a significant effect.

A variety of nonnitrogenous oxygenated compounds gave false-positive alkaloid reactions with Dragendorff's spray reagent. These compounds reacted positively if the oxygen function and the β-carbon bonded to the oxygen had high electron density. Thus, aldehydes, ketones, lactones, ethers, esters, epoxides, and peroxides with an ethylene bond or free alkyl groups at the β-carbon gave a positive reaction, provided that the availability of electrons at the oxygen and the β-carbon was not altered by electron withdrawal or hydrogen bonding. Carbonyl, ether, and ethylene functions were shown by IR evidence to be involved in coupling. Nitrogen-free, alkaloid-like acetone artifacts were obtained by interaction with fixed alkali and with acids. These compounds were postulated to be α,β-unsaturated aldol condensation products of acetone. Interaction with ammonia in addition yielded nitrogenous alkaloid-like artifacts.

The acidic vs. alkaline difference spectra of cinnamic acid, benzoic acid, and total resin acids of tolu, benzoin, and colophony were studied. Characteristic maxima, minima, and isosbestic points of these spectra led to the development of a method for the quantitation of the individual balsamic acids and complete elimination of the spectral interference due to resin acids.

In a previous work, a difference spectrophotometric method was developed for quantitating benzoic and cinnamic acids, in the presence of resin acids. In the present work, the technique was adapted for estimating the individual balsamic acids in balsam tolu and benzoin. A procedure for determining purity of the balsamic acids fraction, recovered after alternative purification steps, was studied. Thus we developed an assay procedure relevant to both balsams. Results by the proposed method, the BPC method, and a literature spectrophotometric method are compared.

Otosenine and senecionine/seneciphyllme were isolated from Senecio aegyptius and S. desfontainei, respectively. Senecionine and seneciphylline easily cocrystallize; m.p. and IR-spectra of mixtures of both alkaloids and their separation by PC are described. IR evidence of individual alkaloids and of the alkaloid-pair are shown.

Santonin gives a characteristic alkaline vs acidic difference spectrum. This was used for its estimation in pharmaceuticals and in the crude drug. Santonin was first extracted and purified through a specific partition procedure; then the difference absorbance was measured either at the maximum, 285 nm, or the minimum, 242 nm. The percentage of santonin can be calculated either by reference to the difference absorbance of a reference santonin sample, treated similarly, or by making use of the determined absorptivity. Measurement at the maximum is advisable, especially when the crude drug is assayed, because natural contaminants may interfere with the difference absorbance at the minimum.

A spectrophotometric method is presented for assaying Senna and its preparations, for both total sennosides and total rhein glycosides content. The method ensures complete elimination of other minor non-carboxylic anthracene derivatives, as well as flavonoidal contaminants. The proposed method quantitates the actual total sennosides content, through the elimination of these contaminants, and through correction for the interference due to the coexistence of rhein with sennidins, in the final determinative step. This would eliminate false high figures for total sennosides by earlier procedures and reflects, perspectively, the actual potency of the assayed samples.